Growth stunting and micronutrient deficiencies are two major problems existing in Peruvian children. To improve growth, research has shown that interventions to improve nutritional intake must focus on the first two years of life. A trial is planned to improve the nutritional status of infants. This community based effectiveness trial will use existing governmental health services and community channels to promote nutrition education. Sustainability and replication throughout Peru and other countries is a desired goal of the trial. Process evaluation of the planned infant feeding trial is the proposed area of research. To date, most public health research has concentrated on the outcome of trials. While crucial to understanding the outcomes of an intervention trial, process evaluation research is sparse. The objectives of the proposed research, a process evaluation, are 1) to determine the degree to which the infant feeding trial is operating effectively, 2) to identify those critical and feasible components of the trial necessary for sustainability 3) provide the detailed operational information necessary for trial replication, and 4) to track the trials activities and make suggestions for improvements (if any) during the life of the trial. Via documentation of this trial, a final objective of the research is to develop a "methods package" for the use of process evaluation in other infant nutrition programs.